WASHINGTON (AP) — A U.S. submarine's deadly attack on an Iranian warship does not appear to have violated international or American military law, though it's not yet clear whether the sub took sufficient measures to rescue nearly three dozen survivors, legal experts said.
Legal questions are swirling about the underpinnings for the entire U.S.-Israeli military operation against Iran, and the aftermath of the torpedo attack on the IRIS Dena in the Indian Ocean, the experts said.
At least 87 people died and 32 Iranian sailors were rescued after the sub torpedoed the Dena in international waters near Sri Lanka.
While the attacks on Iran overall are “a clear violation of the UN charter,” the Dena was “a clear military target,” said Marko Milanovic, professor of international law at the University of Reading in Britain.
"Targeting a military vessel is not a war crime,” Milanovic said.
The vessel had just participated in naval exercises hosted by India and was heading into international waters on its way home, the Indian government said.
But neither its location far from the war zone nor its presence for the joint naval exercises affects the legality of the strike, said Rachel VanLandingham, a professor at Southwestern Law School and a retired lieutenant colonel in the U.S. Air Force who served as a judge advocate general.
“It doesn’t matter that it wasn’t firing at the time," she said of the Iranian ship. "It matters that it can be used to fire at American military assets.”
But what transpired after the torpedo struck the ship could raise concerns.
“The attack may not violate the law of war, but that’s only the start of the analysis,” said Brian Finucane, who served in the State Department's Office of the Legal Adviser for a decade. “What happens after the attack is another matter.”
International humanitarian law says the U.S. should have taken “all possible measures” to help search for and collect anyone who was wounded or shipwrecked.
U.S. naval forces have the same obligation under the Pentagon's rules as laid out in the Defense Department Law of War Manual. But the manual notes that “practical limitations,” including the cramped quarters of a submarine, could require it to alert other ships, airplanes or nearby authorities of the location of possible survivors.
Bringing people inside a submarine -- one of the most closely guarded platforms in the U.S. Navy -- also poses issues.
A U.S. official confirmed that following the strike, the United States contacted Sri Lankan authorities to provide them with the ship’s location for search and rescue efforts. The official spoke on condition of anonymity in order to discuss matters that were not authorized for release.
Sri Lanka's foreign minister, Vijitha Herath, told Parliament that Sri Lanka's navy received a distress signal from the stricken ship, and sent ships and planes on a rescue mission.
But by the time Sri Lanka’s navy reached the location, there was no sign of the ship, “only some oil patches and life rafts,” navy spokesman Commander Buddhika Sampath said. “We found people floating on the water.”
Finucane said that without more information, “it’s hard to evaluate whether there were possible measures they could have taken. But at a minimum, they should be explaining this.”
Eugene R. Fidell, who teaches military law at Yale Law School, said it “may be a long time before we have a full account of who did what and when in the aftermath of the attack. If as it appears, they alerted the coastal authorities, they did right to do so.”
But even then, difficult questions remain, Fidell said, principally whether rescuers were close enough to the scene. “So until we get more clarity, granular clarity, I think it’s premature to make any judgments,” he said. “I’m being circumspect, but I think It’s important to be circumspect.”
Quell reported from The Hague.
Two Iranian sailors, center, who were rescued from IRIS Dena warship by Sri Lanka's navy are escorted to a Judicial Medical Officer from the National Hospital, in Galle, Sri Lanka, Thursday, March 5, 2026. (AP Photo/Eranga Jayawardena)
Two Iranian sailors, carrying green bags, who were rescued from IRIS Dena warship by Sri Lanka's navy are escorted to a Judicial Medical Officer from the National Hospital, in Galle, Sri Lanka, Thursday, March 5, 2026. (AP Photo/Eranga Jayawardena)
